Hitherto, herbicidal activity of tetrahydrophthalamic acid derivatives has been well known. For example, N-(4'-chlorophenyl)-3, 4, 5, 6.tetrahydrophthalamic acid methyl ester is known, as is disclosed in JP-A (Patent) 48-44425.
However, the conventional tetrahydrophthalamic acid derivatives are not necessarily sufficient in herbicidal activity, or are substantially limited in herbicidal spectrum against weeds. Furthermore, these derivatives are insufficient in selectivity between crops and weeds, thereby inducing problems of safety for crops. Compounds disclosed in JP-A (Patent) 4-803407 are known as those solving these problems and exhibiting excellent herbicidal activity. However, there is no description about compounds having N-aryloxyacyl group in N-acyl group part nor about biological activity of these compounds.
It is an object of the present invention to solve the aforementioned conventional problems, and to provide N-aryloxyacyl-N-phenyltetrahydrophthalamic acid derivatives as novel compounds exhibiting excellent herbicidal activity against various very harmful weeds and not being harmful to crops, methods of producing the same and herbicides containing the same as the effective components.